Watch over prayers and especially the Middle Prayer

The Al-mighty said: {Watch over prayers and [especially] the Middle Prayer; and stand up devoutly to [worship] God.}[1], what is the ‘Middle prayer’?

This believer feels intense constriction

So the believer for whom this world becomes a prison, constricted and of limitless pain,
and it does not end except by exiting it through death; is the believer who ascends
during his prayers to the seven skies.